A&P1 Exam4

Neuron Structure and Function

  • Dendrites: Bring information into the soma.
  • Soma (Cell Body): Contains the nucleus and integrates signals.
  • Axon: Takes information away from the soma.

Myelin

  • PNS: Schwann cells produce myelin.
  • CNS: Oligodendrocytes produce myelin.
  • Composition: Myelin is made up of lipids and proteins.
  • Purpose: Acts as insulation to speed up signal transmission along the axon.

Action Potential

  • Ion Movement:
    • Depolarization involves Na^+ influx.
    • Repolarization involves K^+ efflux.
  • Terms:
    • Depolarization: Membrane potential becomes less negative.
    • Repolarization: Membrane potential returns to resting state.
    • Action Potential: Rapid change in membrane potential that propagates along the axon.
    • Threshold: Minimum level of depolarization required to trigger an action potential.
    • Local Potentials: Small changes in membrane potential that can summate to reach the threshold.

Spinal Cord

  • Overlap between Lab and Lecture: Understand the structure and function of the gray and white matter, dorsal and ventral horns.
  • End Point: The spinal cord ends around the L1-L2 vertebral level.
  • Meninges:
    • Dura Mater: Outermost layer.
    • Arachnoid Mater: Middle layer.
    • Pia Mater: Innermost layer.

Brain Parts

  • Lobes: Frontal, Parietal, Temporal, Occipital.
  • Gyri: Ridges on the surface of the brain.
  • Sulci: Grooves on the surface of the brain.
  • Separations:
    • Longitudinal Fissure: Separates left and right hemispheres.
    • Central Sulcus: Separates frontal and parietal lobes.

Broca's and Wernicke's Areas

  • Broca's Area: Located in the frontal lobe; involved in speech production.
  • Wernicke's Area: Located in the temporal lobe; involved in understanding language.

Brain Function Localization

  • Planning: Frontal lobe.
  • Vision: Occipital lobe.
  • Memory and Learning: Hippocampus (temporal lobe).
  • Emotions: Limbic system (amygdala, hippocampus).
  • Balance: Cerebellum.

Autonomic Nervous System

  • Fight-or-Flight (Sympathetic): Prepares the body for action.
  • Rest and Digest (Parasympathetic): Promotes relaxation and digestion.

Nervous System Names

  • Sensory (Afferent): Carries signals to the CNS.
  • Motor (Efferent): Carries signals from the CNS to muscles or glands.

Neurotransmitters

  • Examples: GABA, glutamate, acetylcholine, dopamine.
  • Functions:
    • Inhibitory (e.g., GABA).
    • Excitatory (e.g., Glutamate).
  • Disorders: Imbalances can be involved in various neurological and psychiatric disorders.

MAO and MAOIs

  • MAO (Monoamine Oxidase): Enzyme that breaks down monoamines.
  • MAOIs (Monoamine Oxidase Inhibitors): Inhibit MAO, increasing monoamine levels in the synapse.
  • Monoamines: Neurotransmitters like dopamine, serotonin, and norepinephrine.

Cerebrospinal Fluid (CSF)

  • Transport: Circulates through ventricles and subarachnoid space.
  • Production: Made in the choroid plexus within the ventricles.
  • Reabsorption: Reabsorbed into the bloodstream via the arachnoid granulations.

Spinal Plexus

  • Cervical Plexus (Neck): Phrenic nerve (diaphragm control).
  • Lumbar Plexus (Lower Back): Femoral nerve.

Reflexes

  • Important Reflexes: include the stretch reflex, withdrawal reflex, and reciprocal inhibition.

Brain Stem

  • Includes the midbrain, pons, and medulla oblongata; responsible for basic life functions.

Limbic System

  • Components: Amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus.
  • Functions: Emotion, memory, and motivation.

Sleep

  • Phases: NREM (Stages 1-3) and REM sleep.
  • REM: Rapid eye movement, dreaming, and muscle atonia.

Cranial Nerves

  • Function: 12 pairs of nerves that emerge directly from the brain; control sensory and motor functions of the head and neck.